Various types of integrated circuit devices have evolved since the development of the semi-conductor. Typical of such devices are DIPs (dual in-line packages), SOICs (small outline integrated circuits), and PLCCs (plastic leadless chip carriers). Such devices have innumerable applications in industry and commerce.
In many of these applications, it is essential that the devices be accurate to at least a defined minimum percentage of accuracy. While, as to some applications, it is essential that the devices be 100% accurate, in other applications, an accuracy of, for example, 80% might be acceptable if certain critical circuit paths are completely accurate. The manufacturing processes for integrated circuits, as in the case of other manufacturing processes, will produce units of different quality. For this reason, it is necessary to test the units not only to answer the question of whether or not they are operable to any degree, but also to classify the units by degree of operability.
Various high speed testing devices have been developed in order to measure the quality of such devices. Typically, such testers can perform testing upon units at very high rates of speed. It is, therefore, necessary to provide handling equipment capable of feeding units to a test site interfacing with the tester rapidly and, similarly, to convey the units away from the test site at a high rate of speed.
Various high speed handlers have been developed to solve this problem. Methods of singulation (that is, methods of isolating a single device from an input track), have been developed and are constantly undergoing a process of improvement. In order to facilitate ever increasing speed requirements, multiple test site handlers have been designed.
Depending upon the type of device and the application to which it is to be put, the device will be subjected to different environmental operating temperatures. For example, in one application, the device which is being tested will ultimately function in an environment with a temperature significantly higher than ambient room temperature.
A particularly important feature of any handler is that it not only serves to effect the singulation function, but also that it brings integrated circuit devices being handled to the temperatures at which they will ultimately operate. One manner in which the prior art has attempted to accomplish this goal is by providing an input magazine which functions as a temperature chamber, the temperature in the chamber being elevated or lowered by introducing a gas of the desired temperature into the chamber to surround the devices as they pass through the magazine. This tack, although, in some degree, solving the problems, is less than completely adequate. This is so for a number of reasons including the fact that, with such a method, there can be an uneven distribution of the thermal energy in the chamber. As a result, devices at a particular location along a track down which the devices pass will be elevated to a certain temperature, while devices at other locations along the track will be elevated to different temperatures. As can be seen, therefore, problems yet remain.
As previously indicated, it is also important that singulation be effected quickly and efficiently. In order to prevent jamming, any singulation method employed should be simple and responsive to signals transmitted to the structure accomplishing the singulation.
The present invention functions to overcome the problems of the prior art and to satisfy these requirements. It is an improved singulation and heating apparatus for use in high speed integrated circuit device handlers.